This application makes reference to, incorporates the same herein, and claims all rights accruing thereto under 35 U.S.C. xc2xa7121 through my patent application entitled Apparatus And Method For Automatically Opening A Cover Of An Ink-Jet Printer earlier filed in the Korean Industrial Property Office on the 29th day of August 1996 and there duly assigned Serial No. 1996/36565.
1. Field of the Invention
The present invention relates to an apparatus and process for automatically opening a cover of an image forming apparatus, and particularly to an improved apparatus and process for automatically opening a cover of an image forming apparatus when there is a change in the operational readiness of the apparatus.
2. Description of the Related Art
In one method for transporting paper in a typical printer, a printing command is given and the paper feeding unit receives a control signal generated by the control unit and then loads the paper into the printer feeding unit. The paper is transported by rotating the feed roller so that the paper passes through the inside of the printer while ink is applied to the paper. One method for applying ink to the paper sprays the ink from a printer head, equipped with a plurality of minute nozzles, onto the paper. The operation of the printer head, along with the other printer operations, is controlled by signals generated by the control unit. After the ink has been applied, the paper is ejected through the ejection orifice of the printer by operation of the paper ejecting unit.
When an error is caused by a paper jam or by a shortage of ink, and the error is found by the user, the user must then follow a series of operations to resume printing. The user must open the cover of the printer, identify or confirm the cause of the error, take some action to correct the error, and then close the cover.
Some processes for simplifying the manual removal of jammed paper have been developed. U.S. Pat. No. 5,182,595 to Fukuchi entitled Image Forming Apparatus Having an Dismountable Process Cartridge, mentions a printer that automatically opens an upper printer cover and partially ejects a process cartridge when a paper jam is sensed. It also mentions the possibility of setting either its printer to open or its process cartridge to be partially ejected, or both, when an ink problem is detected. I have noticed, however, that the mechanism used by the Fukuchi ""595 patent to allow a user to see the inside of the printer is a complicated two step process in which both the upper printer cover must be opened and the process cartridge partially ejected. The cover opening mechanism is a complicated combination of gears, micro-switches, and also uses a camming element inside the main body of the printer. It uses multiple gears to rotate the upper printer cover. This necessitates using a movable projection, connected to the rotation axis of the cover, to allow for the smooth rotation of the gear located at the axis.
U.S. Pat. No. 5,172,117 to O""Dea entitled Image forming Apparatus Having an Openable Sheet Guide, shows a printer with a top half that can be manually opened to allow rollers to separate and aid the user in removing the jammed paper. The O""Dea ""117 device requires manual action by the user to gain access to the interior of the printer.
U.S. Pat. No. 5,307,116 to Ikunami entitled Image Forming Apparatus Provided with Unit Locking Means, uses solenoids to lock portions of a copier in place and thereby prevent a lack of structural stability, due to the over extraction of components, and also to control the order in which a user is allowed to remove components from the copier. Ikunami ""116 uses the solenoids merely as a restraint for different components of the copier. The solenoids can later be switched to an unlocked position so that the user may manually remove the corresponding part. The design of the solenoid switch causes a latch to rotate about an axis at the distal end, opposite the end on which the latch is located, by pulling on a point roughly midway along the latch with a solenoid. Ikunami ""116 controls the order in which components can be removed by the user.
Various processes have been disclosed for locating the source of a paper jam. U.S. Pat. No. 4,908,655 to Takagi entitled Jam Detecting and Displaying Device in an Image Recording Apparatus, uses lights attached to the printer to help the user locate the paper jam. U.S. Pat. No. 4,176,941 to Breitenkam entitled Malfunction Display System for Electrophotographic Copying Machines, uses lights on a schematic diagram to aid users in identifying the cause of jams.
I have observed that when users unfamiliar with a printer have to remove a paper jam or replace an exhausted ink container that there is often difficulty in identifying and correcting the problem. I believe that an automatically opening printer cover would be a great aid to unfamiliar users and make their use of the printer more efficient. Ink-jet printers tend to be less expensive than other more advanced printers on the market today, but unfortunately, they also have a correspondingly lower profit margin on their sale. To be effective, I expect that the mechanism for opening the printer cover must be simple to construct and unlikely to malfunction or need repair. I have found that what is needed, but so far unaddressed by the art, is a new mechanism and process for automatically opening the cover when an error occurs, that is economical to construct, simple, and particularly well suited to the economic limitations, technological level and the physical configuration of a typical ink-jet printer, so as to aid the unfamiliar user in identifying and correcting printer errors.
It is an object of the current invention to provide a process and an apparatus for automatically opening the cover of an image forming apparatus.
It is another object to provide a simple mechanism capable of opening covers of image forming apparatuses such as an ink-jet printer.
It is still another object to provide a mechanism for opening the cover of an image forming apparatus that is simple to construct and unlikely to malfunction or need repair.
It is yet another object to provide a low cost mechanism for automatically opening the cover of an image forming apparatus.
It is yet still another object to provide a process by which covers of printers can be automatically opened when there is a paper jam or when the ink in the printer""s ink cartridge is exhausted.
These and other objects may be achieved with a solenoid mechanism to automatically open the cover of an image formation device such as an inkjet printer. This mechanism uses a solenoid, an attached spring and a plurality of latches, and is both very simple and economic to use in lower profit margin printers, such as ink-jet printers. The design of the automatic cover opening mechanism is streamlined so as to require minimum maintenance. It is constructed with a movable latch located on the side of the main body of the printer that faces the inside of the printer cover. The non-interlocking side of the latch is attached to a spring that is fixed at its other end to a solenoid. A second stationary latch is fixed onto the inside of the printer cover and can be interlocked with the first latch. The solenoid separates the first latch, located on the side of the main body or the printer, from the second latch, located on the inside of the cover, by pulling the spring and thereby causing the latches to disengage in response to an electrical signal received from a controller unit.
A process for automatically opening a cover of an ink-jet printer according to the present invention may be practiced by using a sensing unit to make a determination of when a paper jam occurs; applying an electrical signal to a controller unit when a paper jam is detected; making a determination of whether ink is exhausted from the cartridge or other ink container; applying a second electrical signal to the controller unit when the exhaustion of ink is detected; and opening the cover of the printer after detaching the connecting unit by operating the solenoid, or other device, under the control of the controller unit in response to the first and second electrical signals.